减压阀能用于液体的减压。
参考答案:错
22. Was it _____the conference of APEC that made Shanghai the focus of the world then?
A.holding
B.to hold
C.held
D.having held
酸轧中间辊辊径的使用范围()
A.520~460mm
B.550~450mm
C.480~390mm
D.580~470mm